1. Field of the Invention
The present invention relates to therapeutic body supports, and in particular, to supports having reciprocating elements.
2. Description of Related Art
Bedridden patients being treated in the hospital or at home can develop bedsores (decubiti) under certain conditions. The Braden Scale evaluates the risk of sores by scoring six categories: (1) The ability of the patient to respond meaningfully to pressure-related discomfort, which may decline as a result of sedation, a diminished level of consciousness, or a limited ability to feel pain. (2) The degree of exposure of the skin to moisture from perspiration, body fluids, etc. (3) The amount of physical activity performed by the patient. (4) The patient""s ability to change and control body position. (5) The adequacy and quality of the patient""s diet. (6) How often the patient moves or must be moved in a way that causes friction and shear forces.
One of the prime contributors to skin breakdown that causes decubiti, is the bill-up of moisture between the patient""s skin and the bedding on which the patient is resting (Braden Scale).
Insensible water loss from a body is approximately 50 ml /hour (xe2x80x9cTextbook of Medical Physiologyxe2x80x99 Guyton and Hall, 2000). When a patient is febrile, the amount of moisture exuded through the skin can increase dramatically. If the patient is also incontinent of bowel and/or bladder, more fluids are exuded and act to increase the damage of shear on skin which promotes decubiti formation.
Existing hospital beds do not allow for free flow of air under the patient. One typically expensive model by Hill-Rom incorporates a mechanical flow of air but is predicated on existence of continual electrical power.
Keeping skin temperature down will also reduce the risk of decubiti. Unfortunately, known bedding systems do not incorporate effective features for reducing or moderating skin temperature.
The prediction of porosity or permeability of fabrics via theoretical models has proven somewhat frustrating (The Relationship Between Porosity and Air Permeability of Woven Textile Fabrics, Epps and Leonas, Journal of testing and Evaluation, Vol. 25, 1997, pp 108-113). Fortunately the measurement of air and moisture is not, and is available for the common fabrics (sheeting, print cloth, flannel, sateen, plain weave, batiste, poplin, and the synthetics: taffeta, challis, and plain weave triacetate).
Rather complicated beds are available for providing a body support that reduces the tendency for bedsores. These beds provide continually changing pressure points that prevent stasis. However, these beds are not widely available because their complexity and cost make them impractical for widespread use in most hospitals, as well as being beyond the financial reach of most home users. Moreover, these beds have many drawbacks in that they do not promote adequate air circulation around the patient, are not easily dismantled for set up or cleaning, cannot be easily operated manually during a power failure, etc.
In U.S. Pat. No. 5,776,048 a burn patient lies on a row of fixed bars 38 interleaved with reciprocating bars 43. The reciprocating bars rise above and descend below the fixed bars to prevent bedsores. The bars have a removable core that can be removed for washing.
In U.S. Pat. No. 4,625,487 a number of transverse cushions are held in cradles to form a bed. Alternate cradles can be rocked in opposite directions to produce alternating lift points that can massage a person and prevent bedsores. See also U.S. Pat. No. 4,494,260 where cradled cushions are all rocked in the same direction.
In U.S. Pat. No. 3,464,406 a bed surface is supported by a number of parallel rods 100, each mounted between an opposite pair of planetary gears 90. The rods 100 are mounted eccentrically and at different phases so that when gears 9 are rotated, the rods produce a wave-like motion.
In FIG. 5 of U.S. Pat. No. 4,999,861 a bed surface is formed from a number of parallel slats 18 with rollers that ride on cams 64, which are phased to produce a wave-like motion. See also U.S. Pat. No. 4,202,326.
In. U.S. Pat. No. 4,958,627 a bed is formed of a number of parallel wires 13. A motor-driven cam swings a lever 32 (FIG. 3) to periodically hit and lift the wires 13 as shown in the upper left portion of FIG. 2.
In U.S. Pat. No. 5,161,267 a patient is lifted by a number of parallel straps in order to change bed linens.
In U.S. Pat. No. 6,009,873 a pair of inflatable wedges are placed on opposite sides of a patient and held in place with encircling straps to maintain the patient""s position.
Accordingly, there is a need for an improved body support and method for supporting a body that can provide a beneficial effect, such as preventing bedsores.
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a body support for providing a beneficial effect. The support includes a first frame having a first plurality of parallel bands, and a second frame having a second plurality of parallel bands. The first plurality of bands is interdigitated with the second plurality of parallel bands. Also included is a driver for reciprocating the first plurality of parallel bands, and the second plurality of parallel bands. The driver produces relative motion between the first and the second plurality of parallel bands.
In accordance with another aspect of the present invention a method is provided that employs a first plurality of parallel bands and a second plurality of parallel bands to support a body while preventing bed sores. The method includes the step of interdigitating the first plurality of bands with the second plurality of parallel bands. Another step is reciprocating the first plurality of parallel bands, and the second plurality of parallel bands by producing relative motion between the first and the second plurality of parallel bands.
In accordance with yet another aspect of the present invention a method is provided that employs a first plurality of parallel bands and a second plurality of parallel bands to support a body while preventing bed sores. The method includes the step of interdigitating the first plurality of bands with the second plurality of parallel bands. Another step is producing relative motion between the first and the second plurality of parallel bands. The method also includes the step of attaching a replacement band end to end with a selected one of the bands of the first and the second plurality of parallel bands. Another step is pulling the selected one of the bands in a direction to insert the replacement band into a position originally occupied by the selected one of the bands.
In a preferred embodiment two separate frames will be fitted with parallel bands. This arrangement will allow bands from one frame to interdigitate with the bands from the other frame. The two frames will be mounted in a support structure and reciprocated with such phasing that bands from one frame will be reaching a peak while bands from the other frame will be reaching a low point. In this preferred embodiment both frames will be moving relative to the support structure and will maintain the bands at an approximately constant average elevation so that a patient lying on the body support will not have the uncomfortable feeling of rising and falling.
Preferably, the parallel bands will be flexible strips that are releasably fastened on opposite sides of their respective frames. This will allow periodic removal of the parallel bands for cleaning or replacement. Preferably, the frames can be placed in positions allowing access to the regions where the bands are attached to the frame to facilitate removal and replacement of the bands. In one preferred arrangement, one end of a replacement band is attached to an end of an original band using a discardable fastener. Thereafter, the original band can be withdrawn in a direction to pull the replacement band into the position previously occupied by the original band.
Apparatus and methods of the foregoing type can be designed to allow air circulation under a patient at all times, even with the motor off, thereby preventing moisture build-up, which is a prime contributor to the development of decubiti (bed sores). Also, preferred embodiments can be designed with an oscillating action that acts as an external heart pump to help blood flow.
Components of the preferred embodiments, when arranged as a bed, can be dismantled for ease of setting up. Also, the underlying bands act as a bedding that can be changed without moving the patient. In the preferred embodiments, the supporting straps can be easily changed for improved sanitation, thereby decreasing the chance for microbial pathogens to infect a patient.
In case of electrical failure or motor failure, the preferred bed oscillating mechanism can be operated in a manual mode, with pressure shifting preserved.
Because the preferred body support is less heavy and can be disassembled, less time is required to move it in and out of a patient""s bedroom. Because the preferred body support can be made from standard components (steel frames, fabric straps, gears, motors, grommets, etc.), it is much easier and less costly to manufacture. Also, because the preferred design is of a simpler nature, costly technical maintenance is reduced. Consequently, more patients will have access to this modality, and thereby more pathology will be successfully treated or prevented.